Mass Air Flow Sensor: Implausible Signal Polo TDI

[Dsldude]

I was doing a routine check with VCDS after I fitted a new coolant temp sender this week, and noticed this error.

16485 - Mass Air Flow Sensor (G70): Implausible Signal.

The car seems to run perfectly as ever though which confuses me, I have tried to clean the maf with maf cleaner but it didn't clear the error.

I took the car for a good blast and logged some stats in VCDS, What doesn't seem right is at idle it can draw about 162mg/str
of air according to the MAF but then at say 2000rpm it says its using less air at 147mg/str, even when I was flooring it at about 3000rpm
in 3rd it was pulling up a hill great and boost showed about 2300mbar, yet the MAF said it was using the same 162mg/str of air?.

Othertimes it reads 539mg/str which I think is a dummy number when the ECU is getting a Implausible Signal.

I have attached the log I did which has these figures in (had to put inside zip as cant attach .xls file)
LOG-01-001-003-010.zip
Am I right thinking this issue would ether have to be a faulty
MAF or a leak after the MAF but before the Turbo?

Just looking for guidance before I buy a new MAF.

Car: 2001 Polo 1.4 TDI 6n2 AMF Engine on 155k miles.

[Crasher]

Just fit a new genuine VW AMM, DO NOT buy aftermarket, they often fail out of the box and send you off on a wild goose chase...

[Dsldude]

Ok So I have fitted the replacement MAF (Bosch) and the error
16485 - Mass Air Flow Sensor (G70): Implausible Signal.
Has now gone and not comeback after a good drive :-)


I still seem to have a slightly lower than spec idle intake air reading of 200 mg/str and if I rev it that seems to travel down a little and not up as expected.


So I had a good look over the intake before the turbo and found the crankcase breather pipe going from rockercover to the nozzle as shown in the photo is missing a spring clip and the area is wet with oil gunk so I guess it could well be pulling air in from there.

InkedLüftschlauch-Turbolader-VW-Audi-SEAT-Skoda-12-TDI_LI.jpg

I dont think the EGR valve is doing a great deal ether at the moment as the duty cycle never seems to change from 20%, but I guess that could all be related.